1. Field of the Invention
The present invention relates to a method and system for establishing data transmission, including packetized voice communication, over a wireless network, such as a cellular network, and, more particularly, relates to a system and a network-initiated method and system for providing an Internet Protocol (IP) setup to enable a data transmission with a wireless terminal using IP.
2. Description of the Related Art
Consumer demand has steadily increased for Voice over Internet Protocol (VoIP) services. In VoIP, a voice message is transmitted as packetized digital data in the same manner as an Internet transmission, rather than as a traditional circuit-switched voice call over the Public Switched Telephone Network (PSTN). VoIP offers savings to an organization with many locations in that a single data network can be used for both data and voice communications. Further, an individual user can make a VoIP call to anywhere in the world by accessing an internet web site and only be charged for web usage. As the demand by consumers for wireless communications increases, analysts predict that consumers will demand VoIP and other IP data transmissions from wireless providers. Apart from VoIP, data communication using wireless terminals is increasing in popularity, with E-mail, text messages, games, software updates, and many other applications being available through wireless networks.
Wireless communication over IP requires that a Packet Data Protocol (PDP) context be established between the wireless terminal and the Serving Gateway Service Node (SGSN). Once the wireless terminal requests and initiates a PDP context with the SGSN, the Global Gatework Service Node (GGSN) assigns an IP address to the wireless terminal and registers that address. Due to the limited number of IP addresses that are assigned to each wireless provider and the very large number of wireless terminals in existence, each wireless terminal cannot have a permanent IP address. Further, the network only assigns a dynamic IP address when the wireless terminal, at the initiative of the user, requests one.
Because a wireless terminal must request and obtain an IP address to establish a PDP context and communicate by IP, a problem arises when an originating terminal or application (for example, a push service) wishes to transmit data via IP to a wireless terminal. Specifically, if the receiving terminal has not previously obtained a dynamic IP address, the originating terminal will not be able to transmit data over a data channel because the receiving terminal, and user, do not know that the originating terminal or application is attempting to set up an IP session. It is, of course, desirable that wireless terminals be able to receive VoIP calls and data transmissions from any number of applications under these circumstances. However, without prompting, there is currently no way for the receiving terminal to know to request and obtain an IP address in this situation.
A common current method of data transmission uses the Short Message Service (SMS). SMS messaging can be used to supply limited amounts of data over the control channel to a mobile terminal. In this regard, the data to be transmitted is contained in the SMS message itself and the messages are of limited length. Although the SMS messages are relatively short, if a large number of SMS messages are sent, a relatively large amount of bandwidth will be required. More specifically, although SMS messages are individually of relatively short duration and the control channel usually has available bandwidth, the concern is that, in the future, the expected increase in SMS transmissions will overload the control channel and require the use of a second or third control channel. In fact, this is already the case in some systems, i.e., the systems currently experience control channel congestion during busy hours, and there are systems which replace one or more voice or data channels with an additional control channel or channels. Because the provision of such a further control channel would be (or is) at the expense of a valuable voice or data channel this is obviously something to be avoided.